Four robbery suspects from Houston are in jail thanks in part to an alert witness who gave police information about them after they robbed a 16-year-old boy Wednesday afternoon in Fort Bend County.

The robbery happened about 3 p.m. in the 14700 block of Wynburn near Bissonnet and Highway 6, according to the Fort Bend County Sheriff's Office.

Deputies said the victim was walking along the road when four men in a green vehicle pulled up beside him. One of the men got out, threatened him with a handgun and stole the boy's iPhone and backpack.

Within a few minutes a witness called the FBCOSO to report a suspicious vehicle on nearby Wynbourn Way Court. The caller said four men were in the vehicle and they had tossed out a backpack. The witness gave police the vehicle's license plate number.

Deputies spotted the vehicle at West Bellfort and Highway 6. They saw a handgun magazine on the back seat. They also found a loaded 9 mm pistol underneath the front seat and a loaded shotgun in the trunk. Deputies also found the victim's stolen property.

The four men in the vehicle were taken into custody. They are identified as Cedarius Smith, 20; Ditalian Kelley, 19; Chidurum Onwuegbu, 20; and Keith Menifee, 21. They face charges of aggravated robbery – used deadly weapon and engaging in organized criminal activity, both first-degree felonies.

They were each being held in the Fort Bend County jail in lieu of $50,000.